The invention relates to a superconducting element with a central section located between two end sections of the superconducting element, the superconducting element comprising: a substrate tape, a buffer layer, a high temperature superconducting (HTS) layer, a first protection layer, and a shunt layer.
A layered HTS structure, comprising a substrate, a buffer layer, an HTS layer, a capping layer and a stabilizer layer, or a corresponding method for its manufacturing, respectively, is known from U.S. Pat. No. 7,774,035 B2.
The invention deals with high temperature superconducting coated tapes and may be employed, in particular, in the fields of building of magnets, rotating machines, machines and devices for energy storage, energy transmission, and energy distribution.
Superconductors are used when large electric currents shall be transported or applied with low ohmic losses. High temperature superconductors, having a critical temperature high enough such that cooling may be done with liquid nitrogen (boiling point at atmospheric pressure about 77K), are inexpensive in cooling. However, due to their thin film nature combined with their ceramic properties, HTS conductors and elements are usually manufactured on substrates (HTS coated conductors); in particular, there are tape type substrates that typically offer some mechanical flexibility to HTS coated conductors. For HTS coated tapes, it is known to deposit the HTS film on a buffer layer deposited on the substrate, in order to achieve a beneficial HTS grain orientation needed for high critical currents. The HTS film is typically covered by a protection layer (also called capping layer) of a noble metal in order to avoid chemical reaction with aggressive environmental compositions (as e.g. acids, salt water, . . . ), and a shunt layer (also called stabilization layer) is deposited on top. The shunt layer shall ensure protection against high current overloads (electrical stabilization), e.g. in case of a quench.
In applications, the HTS coated conductors are usually electrically connected one to other in order to provide a functional device or element to be employed in e.g. magnet, cable, motor, fault current limiter.
However, the time stability of superconducting elements being composed or formed from HTS coated tapes is not sufficient enough which is due to reduction of critical current and deterioration of mechanical parameters, e.g. of critical bending radius. Especially this is valid in superconducting elements that undergo electrical quench or are exploited in conditions where minimization of Joel's losses are important.
It is an object of the invention to provide a superconductive element with improved electrical stabilization and time stability and a method for manufacturing such a superconducting element. Further object is to suppress Joel's losses in the superconducting element.